I’m writing this week’s Letter to you from Kirkwall in Orkney. Alistair Carmichael and Jim Wallace have been trying to persuade me to make the trip for a while and I’ve finally made it in order to join the celebrations of the centenary of Jo Grimond’s birth.

The big debate this week in British politics, which featured strongly in PMQs – where I was standing in for the PM (you can watch it here) – has obviously been about our future role in Europe. An issue on which Jo Grimond was a pioneer and leader.

What’s emerging in this debate is that there are three basic positions. The first is UKIP’s and an increasingly large number of Conservatives’ – they want to leave now. I am clear that would be a calamitous mistake for the country – it would make us poorer, make us less safe and jeopardise millions of jobs and billions of pounds of investment.

The second position is the Conservatives’ official position (at least for now) which amounts to saying to the rest of the EU that they should keep all the EU rules for themselves, but we’ll only abide by the bits we like. It’s a have-your-cake-and-eat it strategy. It might sound seductive, but it’s unlikely to work. Instead it will end up with either largely symbolic concessions from the other 26 member states “inconsequential” in Lord Lawson’s words – or demanding so much that the other EU countries will simply refuse.

The third position is the Liberal Democrats’ position. Of course the EU has to change. It is going to change because it’s in a state of challenge and flux and so needs reform. It must be more competitive, more open, leaner and less bureaucratic. All things Britain should lead from the front on and work constructively with our European partners to achieve.

That is a vision of Europe and Britain’s role in it that our party has long subscribed to. And importantly, it is actually achievable.

And in line with our previous manifesto, and the legislation we passed in 2011, when the EU rules change and new things are asked of the UK within the EU, the British people will have a say in a referendum. We are the first Government ever to give the British people such a guarantee in law.

So there are three positions: we can leave now; we can try and (almost certainly fail) to have our cake and eat it; or we can play our part at the heart of Europe promoting reform and guaranteeing a referendum when the EU rules change affecting Britain.

But as I argued in PMQs to the Tory backbenchers (who by the way seem to have developed an almost unhealthy interest in our Focus leaflets!), people are facing more pressing issues. And it is exactly those issues Liberal Democrats in this Coalition Government are currently taking a lead in tackling.

We won’t always get the attention or coverage we deserve for things we are doing, such as introducing Steve Webb’s single tier pension or the important work Norman Lamb has been talking about this week on Social Care. But we will keep delivering these things that make a real difference to people’s lives.

That is what we are in Government for: anchoring it in the centre ground and building a stronger economy and a fairer society. I’m sure Jo wouldn’t have wanted it any other way.